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Figure 4-2: the status byte register (sbr) -5, Table 4-1: sbr bit functions -5 – Tektronix AFG3000 User Manual

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Status and Events

AFG3000 Series Arbitrary/Function Generators Reference Manual

4-5

Status Byte Register (SBR). The SBR is made up of 8 bits. Bits 4, 5 and 6 are
defined in accordance with IEEE Std 488.2-1992 (see Figure 4-2). These bits are
used to monitor the output queue, SESR, and service requests, respectively.

Figure 4-2: The Status Byte Register (SBR)

Table 4-1: SBR bit functions

Bit

Function

7 (MSB)

OSB

Operation Status Bit. Indicates that an operation event has occurred.

6

RQS

Request Service. When the instrument is accessed using the GPIB
serial poll command, this bit is called the Request Service (RQS) bit
and indicates to the controller that a service request has occurred (in
other words, that the GPIB bus SRQ line is LOW). The RQS bit is
cleared when serial poll ends.

6

MSS

Master Status Summary. When the instrument is accessed using the
*STB? query, this bit is called the Master Status Summary (MSS) bit
and indicates that the instrument has issued a service request for one
or more reasons. The MSS bit is never cleared to 0 by the *STB?
query.

5

ESB

Event Status Bit. This bit indicates whether or not a new event has
occurred after the previous Standard Event Status Register (SESR)
has been cleared or after an event readout has been performed.

4

MAV

Message Available Bit. This bit indicates that a message has been
placed in the output queue and can be retrieved.

3

QSB

Questionable Status Bit.

2

EQS

Error/Event Queue Summary.

1-0

–––––

Not used

RQS

RQS

ESB

ESB

MAV

MAV

MSS

MSS

7

6

5

4

3

2

1

0

5

4

3

2

1

0

6

OSB

OSB

QSB

QSB

EQS

EQS